EVALUATION OF A CHEMICAL MARKER FOR PROCESS LETHALITY MEASUREMENT AT 110C IN A CONTINUOUS-FLOW HOLDING TUBE

Meat beads containing glucose precursor of a chemical marker and algin ate beads containing spores of Bacillus stearothermophilus were prepar ed and subjected to steam heating at 110C for selected time intervals. Marker yields were related to spore survivor data and lethality value s obtained from time-temperature data to generate calibration curves. Meat balls, fabricated with meat (marker precursor) and alginate (micr obial spores) beads placed at the center, were heated at 110 +/- 0.5C for selected time intervals (0-55 min) in a continuous flow holding tu be. During the heat treatment, the particles were held stationary in t he holding tube while the carrier fluid (0.5% CMC solution) was circul ated at 2.6 gallons per min. Transient time-temperature responses of t he panicles were recorded at bead locations during test runs. All trea ted samples were analyzed for marker yield as well as spore survivors. Using the calibration curves and marker yield data under test conditi ons, the corresponding spore count reduction and accumulated lethaliti es were computed. Lethalities and spore count reductions calculated fr om marker yield data showed good correlations with those obtained from the experiment. The results indicate that the chemical marker has goo d potential to provide data on accumulated lethality and spore count r eductions. Prior to extension of this approach to aseptic processing c onditions, additional kinetic data on spore destruction and marker for mation should be gathered at temperatures applicable to these processe s.